Expression Of Immune Co-stimulatory Molecule B7-H1and The Effect Of Chemotherapy In Breast Cancer On It

Objectives: To explore the expression and distribution of B7-H1in breast cancer andthe relationship between B7-H1and clinical pathological features. To study the effect ofdifferent types of chemotherapy drugs on the expression and distribution of B7-H1inbreast cancer cell line MDA-MB-231.Methods:1, Expression and distribution of B7-H1protein was detected byimmunohistochemical method in212cases of breast cancer tissues and91cases of benignbreast tissues. Its relationship with the clinical pathology was analyzed by statisticalmethod.2, MDA-MB-231cell line was treated respectively by epirubicin (0,0.4,0.8,1.6μ g/mL) and docetaxel (0,0.5,1,2μ g/mL), expression and distribution of B7-H1wasdetected by immunocytochemistry; expression of B7-H1mRNA was detected RT-PCR;expression of B7-H1in extracted total, cytoplasm and nuclear protein samples wasdetected by Western Blot.Results:1, Expression of B7-H1in breast cancer tissues and benign breast tissues.Inbreast cancer tissues B7-H1proteins expressed in the cell membrane and cytoplasm, a fewalso expressed in the nuclei. The positive rate of expression of B7-H1in breast carcinomawas53.3%, significantly higher than that of benign breast lesions (28.6%), the differencewas statistically significant (P<0.05). In breast cancer tissues, the positive rate of B7-H1was associated with clinical staging, Her-2and Ki67(P<0.05), but not with age, ER, PRand lymph node metastasis.2, Effects of chemotherapy drugs on the expression anddistribution of B7-H1molecule in MDA-MB-231. The results of immunocytochemistryshowed: B7-H1protein was expressed mainly in the cytoplasm and nucleus ofMDA-MB-231cell line, the expression of B7-H1in cytoplasm and nucleus both increasedwith the increasing doses of epirubicin, and the nucleus is particularly significant.But withthe increasing doses of docetaxel the change of expression of B7-H1in cytoplasm andnucleus is not obvious.3, Effect of chemotherapy drugs on the expression of B7-H1mRNA in MDA-MB-231cell lines.In a certain range the mRNA of B7-H1increased with theincreasing doses of chemotherapy drugs (epirubicin, docetaxel)， the difference wasstatistically significant (P<0.05).4, Effect of chemotherapy drugs on the expression ofB7-H1protein in cytoplasm and nucleus of MDA-MB-231cell line.Western Blot resultsshowed that after treated with different concentrations of epirubicin and docetaxel, theexpression of B7-H1in total, cytoplasm and nucleus of breast cancer cells increased andthe increase was dose-dependent, the difference was statistically significant(P<0.05).Epirubicin and docetaxel upregulated the expression of B7-H1in the nucleus ofbreast cancer more obvious than cytoplasm.Conclusions: The expression of costimulatory molecule B7-H1was abnormal high inbreast cancer and the expression was positively associated with clinical staging, Her-2andKi67, showed that B7-H1might participate in the genesis and development of breastcancer; Epirubicin and docetaxel both upregulated the expression of B7-H1inMDA-MB-231cell line, and upregulated more in nuclus than in cytoplasm,showed thatchemotherapy (epirubicin, docetaxel)can change the expression of B7-H1in breast cancercells, the mechanisms and clinical significance need further study.